Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway.
J Sports Sci Med. 2020 Nov 19;19(4):727-734. eCollection 2020 Dec.
The purposes of this study were to establish relationships between selected underwater kinematics and the starting and turning performances and to quantify kinematic differences between these segments in sprint butterfly swimming. Fourteen male swimmers performed 50 m maximal butterfly swimming in a short course pre-calibrated pool. The entire race was filmed by a multi-camera system, which quantified the forward head displacement and velocity ( ) throughout the race with a sampling frequency of 50 Hz. The time taken between 0-15 m ( ) and 25-35 m ( ) as well as 16 kinematic variables were acquired from the data provided by the system and manual video processing for further analysis. The mean underwater velocity ( ) was related to both and (r = -0.70 and -0.95, respectively; p < 0.01). was positively correlated with during the first kick (r = 0.84, p < 0.001) in the start segment and with during the last kick in the turn segment (r = 0.68, p < 0.01), but other kinematic variables such as kick frequency, body angle, deceleration during kicks ( ), and glide time were not related to . Swimmers had larger at the beginning of the segment and during the first kick in the start than in turn segment (p < 0.001). However, during the last kick was similar due to the larger (p < 0.05) in the start than in turn segment. The underwater time was similar between the segments despite a longer underwater distance (p < 0.01) and a larger kick count and frequency (p < 0.01) in the start than turn segment. In conclusion, is an important factor for start and turn performances, but swimmers select individual kinematic strategies to achieve a large . Results also highlighted the importance of the different parts within the underwater segment in each segment.
本研究的目的是建立选定的水下运动学与出发和转身表现之间的关系，并量化蝶泳冲刺中这些阶段的运动学差异。14 名男性游泳运动员在一个短池的校准泳池中进行了 50 米最大蝶泳。整个比赛由一个多摄像机系统拍摄，该系统以 50 Hz 的采样频率量化了整个比赛过程中的头部前向位移和速度（ ）。0-15 米（ ）和 25-35 米（ ）之间的时间以及 16 个运动学变量都是从系统提供的数据和手动视频处理中获得的，以便进一步分析。平均水下速度（ ）与 和 均相关（分别为 r = -0.70 和 -0.95；p < 0.01）。在出发阶段， 与第一踢（r = 0.84，p < 0.001）期间的 呈正相关，而在转身阶段的最后一踢（r = 0.68，p < 0.01）期间与 呈正相关，但其他运动学变量，如踢频、身体角度、踢腿过程中的减速（ ）和滑行时间与 无关。在分段的开始和第一踢时，游泳者的 较大（p < 0.001），而在转身时则较小。然而，由于出发时的 较大（p < 0.05），因此最后一踢时的 相似。尽管出发时的水下距离较长（p < 0.01），且踢腿次数和频率较大（p < 0.01），但两段的水下时间相似。总之， 是出发和转身表现的重要因素，但游泳者会选择个体运动学策略来实现较大的 。结果还强调了水下段不同部分在每个段中的重要性。
